An actuator unit is generally known and is used in safety-related three-phase circuits in order to ensure safe emergency disconnection of the three-phase circuit even if one of the contactors fails.
In the prior art, the drive unit is often arranged well away from the contactors. A large number of cables must therefore be laid between the contactors and the drive unit. In particular, at least two supply lines and at least one return signaling line must be laid for each contactor.